Develop Reference

Background Location service on Android

I'm looking a way to get distance travelled by the user. On purpose I try services like this
public class GPSService extends Service {
private LocationListener listener;
private LocationManager locationManager;
private List<Location> locationList = new ArrayList<>();
private float distancetracking = 0;
private int j = 0;
private float finaldist = 0;
String provider;
public IBinder onBind(Intent intent){
return null;
}
#SuppressLint("MissingPermission")
#Override
public void onCreate() {
super.onCreate();
listener = new LocationListener() {
#Override
public void onLocationChanged(Location location) {
locationList.add(location);
Intent i = new Intent("location_update");
while (j < locationList.size() - 1) {
Location loc1 = locationList.get(j);
Location loc2 = locationList.get(j + 1);
distancetracking += loc1.distanceTo(loc2);
j++;
}
Log.d("service", String.valueOf(distancetracking));
finaldist = distancetracking/1000;
i.putExtra("coordinates", finaldist);
sendBroadcast(i);
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
#Override
public void onProviderEnabled(String provider) {
}
#Override
public void onProviderDisabled(String provider) {
Intent i = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(i);
}
};
locationManager = (LocationManager) getApplicationContext().getSystemService(Context.LOCATION_SERVICE);
Criteria criteria = new Criteria();
provider = locationManager.getBestProvider(criteria, false);
locationManager.requestLocationUpdates(provider,0,0,listener);
}
#Override
public void onDestroy() {
super.onDestroy();
if (locationManager != null){
locationManager.removeUpdates(listener);
}
locationList.clear();
}
}
But when my app goes in background the location didn't receive any location...I was aware of some limitation but actually I didn't understand what to do. I'have to do that on purpose to calculta CO2 from the distance travelled

Android Try Getting location for X seconds without freezing the app

What am i trying to do is to get the GPS location from 2 providers, the first one is the GPS which is the most accurate, the second one is the aGPS which is a combination of GPS and network. I am doing that because aGPS can get location even in tall buildings when normal gps takes more time to get.
What i want is to try getting location from the first provider(GPS) for 10 seconds, if in those 10 seconds i get a location!=null, i break the timed loop and take the result to the main thread, which is the main activity. ELSE ill take the location from the second provider(aGPS) if available. If none of the provider where able to get a location, i will return null after the 10 seconds.
The problem i am facing is, when i do a timed loop, the app freezes for 10 seconds so im not able to get the location to the main activity.
Here i am trying to get the location on the HomeActivity class that extends Activity:
Button btnRedCross = (Button) this.findViewById(R.id.btnRedCross);
btnRedCross.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
OutRequestsDatabaseHandler db =new OutRequestsDatabaseHandler();
OutRequest outreq = new OutRequest();
outreq.setName("Red Cross");
//TODO get the message from LocalUser db
Calendar cal = Calendar.getInstance();
outreq.setDate(cal.getTimeInMillis());
outreq.setMessage("My Message");
outreq.setType("RedCross");
//outreq.setLongitude(12.123456);
//outreq.setLatitude(12.123456);
db.addOutRequest(HomeActivity.this, outreq);
//HERE I AM TRYING TO GET THE LOCATION
GPSTracker locationtracker=new GPSTracker(HomeActivity.this);
location=locationtracker.getLocation();
Log.i("LocationGetter","Result: Longitude:"+location[0]+" Latitude:"+location[1]);
}
});
}
This is the GPSTracker Class where the 2 providers try to get location:
public class GPSTracker{
Context con;
LocationManager locMgr;
private double longgps;
private double latgps;
private double longnetwork;
private double latnetwork;
private LocationListener gpsLocationListener;
private LocationListener networkLocationListener;
public GPSTracker(final Context context){
con = context;
locMgr = (LocationManager) context
.getSystemService(Context.LOCATION_SERVICE);
LocationProvider high = locMgr.getProvider(locMgr.getBestProvider(
createFineCriteria(), true));
LocationProvider low = locMgr.getProvider(locMgr.getBestProvider(
createCoarseCriteria(), true));
//GET LOCATION FROM GPS
gpsLocationListener = new LocationListener() {
#Override
public void onStatusChanged(String provider, int status,
Bundle extras) {
}
#Override
public void onProviderEnabled(String provider) {
}
#Override
public void onProviderDisabled(String provider) {
AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(
context);
alertDialogBuilder
.setMessage(
"Please Enable GPS and Network For Accurate Result")
.setCancelable(false)
.setPositiveButton("Enable GPS",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,
int id) {
Intent callGPSSettingIntent = new Intent(
android.provider.Settings.ACTION_LOCATION_SOURCE_SETTINGS);
context.startActivity(callGPSSettingIntent);
}
});
alertDialogBuilder.setNegativeButton("Cancel",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
dialog.cancel();
}
});
AlertDialog alert = alertDialogBuilder.create();
alert.show();
}
#Override
public void onLocationChanged(Location location) {
longgps = location.getLongitude();
latgps = location.getLatitude();
//Log.i("LocationGetter", "GPS: Longitude:" + longgps+ " Latitude:" + latgps);
}
};
locMgr.requestLocationUpdates(high.getName(), 0, 0f,gpsLocationListener);
//GET LOCATION FROM GPS + NETWORK
networkLocationListener=new LocationListener() {
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub
}
#Override
public void onProviderEnabled(String provider) {
// TODO Auto-generated method stub
}
#Override
public void onProviderDisabled(String provider) {
// TODO Auto-generated method stub
}
#Override
public void onLocationChanged(Location location) {
longnetwork = location.getLongitude();
latnetwork = location.getLatitude();
//Log.i("LocationGetter", "Network: Longitude:"+ longnetwork + " Latitude:" + latnetwork);
}
};
locMgr.requestLocationUpdates(low.getName(), 0, 0f,networkLocationListener);
}
public static Criteria createFineCriteria() {
Criteria c = new Criteria();
c.setAccuracy(Criteria.ACCURACY_FINE);
c.setAltitudeRequired(false);
c.setBearingRequired(false);
c.setSpeedRequired(false);
c.setCostAllowed(true);
c.setPowerRequirement(Criteria.POWER_HIGH);
return c;
}
public static Criteria createCoarseCriteria() {
Criteria c = new Criteria();
c.setAccuracy(Criteria.ACCURACY_COARSE);
c.setAltitudeRequired(false);
c.setBearingRequired(false);
c.setSpeedRequired(false);
c.setCostAllowed(true);
c.setPowerRequirement(Criteria.POWER_HIGH);
return c;
}
public double[] getLocation() {
double location[] = new double[2];
Calendar cal = Calendar.getInstance();
Long endtime = cal.getTimeInMillis() + 10000;
while (Calendar.getInstance().getTimeInMillis() < endtime) {
if (longgps != 0 && latgps != 0) {
location[0] = longgps;
location[1] = latgps;
Log.i("LocationGetter", "GPS: Longitude:" + location[0]
+ " Latitude:" + location[1]);
break;
} else if (longnetwork != 0 && latnetwork != 0) {
location[0] = longnetwork;
location[1] = latnetwork;
Log.i("LocationGetter", "Network: Longitude:" + location[0]
+ " Latitude:" + location[1]);
}
}
locMgr.removeUpdates(networkLocationListener);
locMgr.removeUpdates(gpsLocationListener);
networkLocationListener = null;
gpsLocationListener = null;
return location;
}
}

Isn't this just a multithreading problem. Instead of doing the work on the main thread, one could create a second thread so that it doesn't matter if that thread is idle for 10 seconds.
Incidentally, instead of relying on any single provider, I think it's better to use all providers and trust them according to their accuracy using a Kalman filter. See my answer here for a simple Kalman filter that seems to work in the context of Android location providers.

Make your GPSTracker class abstract by declaring the method updatedLocation(Location loc) without body. In code
public abstract class GPSTracker{
.......
private Location mLocation;
public void updateLocation(Location loc);
private CountDownTimer mNetworkCountDown = new CountDownTimer(10000, 10000)
{
#Override
public void onTick(long millisUntilFinished)
{
}
#Override
public void onFinish()
{
// this onFinish() will be called if not cancel by Gps
locMgr.removeUpdates(networkLocationListener);
updateLocation(mLocation);
}
};
private CountDownTimer mGpsCountDown = new CountDownTimer(10000, 10000)
{
#Override
public void onTick(long millisUntilFinished)
{
}
#Override
public void onFinish()
{
locMgr.removeUpdates(gpsLocationListener);
}
};
.........
gpsLocationListener = new LocationListener() {
..........
#Override
public void onLocationChanged(Location location) {
// Get a gps fix cancel both countdowns and listeners
mGpsCountDown.cancel();
mNetworkCountDown.cancel();
locMgr.removeUpdates(gpsLocationListener);
locMgr.removeUpdates(networkLocationListener);
// The calling class will get the fix
updateLocation(location);
longgps = location.getLongitude();
latgps = location.getLatitude();
//Log.i("LocationGetter", "GPS: Longitude:" + longgps+ " Latitude:" + latgps);
}
};
locMgr.requestLocationUpdates(high.getName(), 0, 0f,gpsLocationListener);
mGpsCountDown.start();
.......
networkLocationListener=new LocationListener() {
..........
#Override
public void onLocationChanged(Location location) {
// No cancelation here, Gps will cancel if it gets a fix
mLocation = location;
longnetwork = location.getLongitude();
latnetwork = location.getLatitude();
//Log.i("LocationGetter", "Network: Longitude:"+ longnetwork + " Latitude:" + latnetwork);
}
};
locMgr.requestLocationUpdates(low.getName(), 0, 0f,networkLocationListener);
mNetworkCountDown.start();
.........
// remove the getLocation()
}
In HomeActivity class create a class that extends GPSTracker
public class HomeActivity extends Activity {
.........
public class MyGPSTracker extends GPSTracker
{
public void updateLocation(Location location)
{
// location would be null if both Gps and Network did not
// get a fix in 10 seconds
if (location != null)
{
// do whatever you want with this location fix
// If you want to know if this fix is from GPS or Network
// just use String provider = location.getProvider()
Log.i("LocationGetter","Result: Longitude:"+location.getLongitude()+" Latitude:"+location.getLatitude);
}
}
}
Button btnRedCross = (Button) this.findViewById(R.id.btnRedCross);
btnRedCross.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
OutRequestsDatabaseHandler db =new OutRequestsDatabaseHandler();
OutRequest outreq = new OutRequest();
outreq.setName("Red Cross");
//TODO get the message from LocalUser db
Calendar cal = Calendar.getInstance();
outreq.setDate(cal.getTimeInMillis());
outreq.setMessage("My Message");
outreq.setType("RedCross");
//outreq.setLongitude(12.123456);
//outreq.setLatitude(12.123456);
db.addOutRequest(HomeActivity.this, outreq);
//HERE I AM TRYING TO GET THE LOCATION
GPSTracker locationtracker=new MyGPSTracker(HomeActivity.this);
// You will get the location when updateLocation is called by the
// MyGPSTracker class
Log.i("LocationGetter","Result: Longitude:"+location[0]+" Latitude:"+location[1]);
}
});
}

get location data from service?

I try to make a locationing service but somehow i cant make it work.
Lat and Lng are always NULL.
I had some exceptions on locManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locListener); so i put it inside a run() method, now exception is gone. What could be the problem?
So what is the solution to make a locationing service work?
Code:
public class LocationService extends Service {
private Timer timer = new Timer();
private LocationManager locManager;
private LocationListener locListener = new MyLocationListener();
private String latitude;
private String longitude;
private String providerToSend;
Messenger messenger;
Timer t = new Timer();
#Override
public IBinder onBind(Intent arg0) {
return null;
}
public void onCreate() {
super.onCreate();
locListener = new MyLocationListener();
locationProviderInit();
startService();
}
#Override
public void onDestroy() {
super.onDestroy();
shutdownService();
}
private void startService() {
locManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
String token = new SharedPreffer(this).loadPreferences("token");
Log.d("Debug - token: ", "Van Token: " + token);
t.schedule(new TimerTask() {
#Override
public void run() {
locationProviderInit();
if (latitude != null && longitude != null) {
Log.d("Debug - lat: ", latitude);
Log.d("Debug - lng: ", longitude);
} else {
Log.d("Debug - lat and lng are: ", "NULL");
}
}
}, 0, 5000);
}
private void locationProviderInit() {
new Runnable() {
#Override
public void run() {
try {
boolean gps_enabled = locManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
boolean network_enabled = locManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
if (gps_enabled) {
locManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locListener);
providerToSend = LocationManager.GPS_PROVIDER;
}
if (network_enabled) {
locManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locListener);
providerToSend = LocationManager.NETWORK_PROVIDER;
}
} catch (Exception e) {
Log.d("Debug", e.toString());
}
}
};
}
class MyLocationListener implements LocationListener {
public void onLocationChanged(Location location) {
if (location != null) {
longitude = Double.toString(location.getLongitude());
latitude = Double.toString(location.getLatitude());
}
}
public void onProviderDisabled(String arg) {
}
public void onProviderEnabled(String arg) {
}
public void onStatusChanged(String provider, int status, Bundle extras) {
}
}
private void shutdownService() {
if (timer != null)
timer.cancel();
Log.i(getClass().getSimpleName(), "Timer stopped!!!");
}
}

you don't execute the Runnable in locationProviderInit...

Have you tried to put a debug message inside the method run() within the Runnable object, and see if it has been ever executed?
Defining a Runnable instance without using it ,e.g. within a thread, won't work.
Here are few examples of open source GPS logging services that you can use as guide.
GPSLoggerService
GPSLoggingService

android: locationManager onLocationChanged does not update Activity

I need your help.
I have a activity that get every 5 min the current lat lon gps = new GpsData(StartActivity.this);. That works fine! But when I left a county and the activity refresh. Then I do not get the current lon lat. I dont know why.
Here is the code:
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.listplaceholder);
btnShowLocation = (Button) findViewById(R.id.report_btn);
btnShowLocation.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View arg0) {
Intent intent = new Intent(StartActivity.this, ReportActivity.class);
startActivity(intent);
finish();
}
});
}
#Override
public void onResume() {
super.onResume();
autoUpdate = new Timer();
autoUpdate.schedule(new TimerTask() {
#Override
public void run() {
runOnUiThread(new Runnable() {
public void run() {
//start GPS
gps = new GpsData(StartActivity.this);
//start json download
new task().execute();
}
});
}
}, 0, 300000); // updates each 5 min
}
class task extends AsyncTask<String, String, Void>
{
private ProgressDialog progressDialog = new ProgressDialog(StartActivity.this);
InputStream is = null ;
String result = "";
protected void onPreExecute() {
progressDialog.setMessage("Status Update...");
progressDialog.show();
progressDialog.setOnCancelListener(new OnCancelListener() {
#Override
public void onCancel(DialogInterface arg0) {
task.this.cancel(true);
}
});
}
#Override
protected Void doInBackground(String... params) {
//get Location Data
double latitude = gps.latitude;
double longitude = gps.longitude;
String mlat = String.valueOf(latitude);
String mlon = String.valueOf(longitude);
//if (gps.latitude != 0.0) {
JSONObject json = jsonFunctions.getJSONfromURL("http://myurl);
Here is my GpsData
public class GpsData extends Service implements LocationListener {
public GpsData(Context context) {
this.mContext = context;
getLocation();
}
public Location getLocation() {
// Get the location manager
locationManager = (LocationManager) mContext.getSystemService(Context.LOCATION_SERVICE);
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this);
return null;
}
/* Request updates at startup */
protected void onStart() {
}
/* Remove the locationlistener updates when Activity is paused */
protected void onPause() {
locationManager.removeUpdates(this);
}
#Override
public void onLocationChanged(Location location) {
latitude = location.getLatitude();
longitude = location.getLongitude();
time = location.getTime();
speed = location.getSpeed();
}
It is simple: I want every 5 min the current lat lon and refresh the List view with the current data from the current county... How can I do this?

Change this
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this);
to
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 300000, 0, this);

Can't find GPS Location

I have a singelton thread-class that sends the gps point to my server. The class holds and refresh the gps position.
FinderThread:
public class FinderThread extends Thread {
private static FinderThread SINGLETON;
public boolean isinterrupt = true;
public int maxage;
public int minage;
public int distance;
public String gender;
public String latitude;
public String longitude;
public String sid;
public Context ctx;
LocationManager gps;
boolean nav;
SharedPreferences pref;
private Handler dlh;
private Handler myLocationHandler;
boolean pause=false;
private FinderThread(Context ctx,Handler dlh, Handler myLocationHandler) {
this.ctx = ctx;
gps = (LocationManager) ctx.getSystemService(Context.LOCATION_SERVICE);
gps.requestLocationUpdates( LocationManager.GPS_PROVIDER,60000, 20, llistener);
pref = ctx.getSharedPreferences("NFF", 0);
sid = pref.getString("sid", "");
this.dlh = dlh;
if (myLocationHandler!=null)
{
this.myLocationHandler = myLocationHandler;
}
if(myLocationHandler != null)
{
myLocationHandler.sendEmptyMessage(0);
}
}
public static synchronized FinderThread getInstance(Context ctx,Handler dlh, Handler myLocationHandler)
{
if (SINGLETON == null) // falls null
{
SINGLETON = new FinderThread (ctx,dlh,myLocationHandler);//instanzieren
}
else
{
SINGLETON.myLocationHandler= myLocationHandler;
SINGLETON.dlh = dlh;
myLocationHandler.sendEmptyMessage(0);
}
return SINGLETON;
}
/*
#Override
public synchronized void start() {
if(SINGLETON != null)
{
SINGLETON.start();
}
}
public synchronized void pause()
{
if(SINGLETON.getState()==State.RUNNABLE || SINGLETON.getState()==State.WAITING)
{
SINGLETON.pause = true;
}
}
public synchronized void tcontinue ()
{
if(SINGLETON.getState()==State.RUNNABLE || SINGLETON.getState()==State.WAITING)
{
SINGLETON.pause = false;
}
}
public synchronized boolean isPaused()
{
return SINGLETON.pause;
}
*/
public synchronized void pause()
{
this.pause = true;
}
public synchronized boolean isPaused()
{
return this.pause;
}
public synchronized void tcontinue ()
{
this.pause = false;
}
#Override
public void run() {
//String locationProvider = LocationManager.GPS_PROVIDER;
//Location lastpoint = gps.getLastKnownLocation(locationProvider);
//longitude = String.valueOf(lastpoint.getLongitude());
//latitude = String.valueOf(lastpoint.getLatitude());
try
{
while (isinterrupt) {
if(!pause)
{
Log.e("NFF", "Finder Thread Begin");
RestConnection r = new RestConnection("finder", dlh, "POST");
r.setParameter("minage", String.valueOf(minage));
r.setParameter("maxage", String.valueOf(maxage));
r.setParameter("distance", String.valueOf(distance));
r.setParameter("gender", String.valueOf(gender));
r.setParameter("latitude", String.valueOf(latitude));
r.setParameter("longitude", String.valueOf(longitude));
r.setParameter("sid", sid);
Log.e("NFF Finder Paramater", String.valueOf(minage)+" "+String.valueOf(maxage)+" "+String.valueOf(distance)+" "+String.valueOf(gender) + " "+String.valueOf(latitude)+" " +String.valueOf(longitude)+ " " + sid );
r.start();
}
Thread.sleep(10000);
}
}
catch (InterruptedException e) {
Log.e("NFF FT", "InterruptedException");
isinterrupt = false;
}
}
private LocationListener llistener = new LocationListener (){
#Override
public void onLocationChanged(Location location) {
if(String.valueOf(location.getLatitude())!= null)
{
latitude = String.valueOf(location.getLatitude());
longitude = String.valueOf(location.getLongitude());
if(myLocationHandler != null)
{
myLocationHandler.sendEmptyMessage(0);
}
}
}
#Override
public void onProviderDisabled(String provider) {
Log.e("NFF", "GPS Disabled");
isinterrupt = true;
}
#Override
public void onProviderEnabled(String provider) {
Log.e("NFF", "GPS Enabled");
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub
}
};
public void saveProperties ()
{
Editor editor = pref.edit();
editor.putInt("maxage", maxage);
editor.putInt("minage", minage);
editor.putInt("distance", distance);
editor.putString("gender", gender);
editor.putString("lat", latitude);
editor.putString("long", longitude);
editor.commit();
}
public void loadProperties ()
{
maxage = pref.getInt("maxage", -1);
minage = pref.getInt("minage", -1);
distance = pref.getInt("distance", -1);
gender = pref.getString("gender", "f");
latitude = pref.getString("lat", "f");
longitude = pref.getString("long", "f");
}
public synchronized void pushSettings()
{
SINGLETON.maxage = maxage;
SINGLETON.minage = minage;
SINGLETON.distance = distance;
SINGLETON.gender = gender;
SINGLETON.latitude = latitude;
SINGLETON.longitude = longitude;
}
}
When i test my app on the emulator and set the position with the emulator control everthing work fine. When i test it on my phone, the droid don't find the position. I have testet the app "GPS Test", there it finds the position within 3 minutes with 5 sattelites.
Please help

It sure looks like you have everything there.
You give yourself the permission in the manifest for FINE_LOCATION, right?
The one suggestion I would make is change your requestLocationUpdates() so that it requests fixes with 0 time between them and 0 distance between them. All GPS recievers I have seen will give you fixes about once a second with this setting, which is pretty much how most gps engines work. Just on the off-chance that the one-minute and 20 m you put in your request are screwing you up. If you get fixes with this suggestion, you can work from there to minimize amount of time gps is on.
Good luck!